1. Field of the Invention
This invention relates generally to latching devices and more particularly to an improved quick release latch for emergency escape applications and other uses.
2. Prior Art
As will become evident from the ensuing description, the improved latch of the invention may be used for a variety of purposes. The improved latch is particularly designed, however, for use as an emergency escape latch for protective window grills and the like. For this reason, the invention will be described in this particular context.
It is becoming ever increasingly necessary to protect building structures against unauthorized entry through windows and other openings and yet permit escape of persons from the structures through such openings in the event of a fire, gas leak, or other emergency. Decorative wrought iron window grills have long been used to provide protection against unauthorized entry through windows and the like. Many window grills were and still are permanently attached to the structures. As a result, persons were and still are often trapped and die in such structures during a fire because of the inability to release or open the window grills. For this reason most if not all city codes now require structures protected by window grills or the like to be provided with quick release window grill latches which can be quickly and easily released by persons within the structures to permit escape of the persons through the windows.
A wide variety of latches for this purpose have been devised. Examples of such latches and other similar latches are described in the following U.S. Pat. Nos.: 2,715,583, 4,019,281, 4,055,360, 4,057,935, 4,070,048, 4,127,966, 4,263,747.
City codes governing protective window grills and latches generally set forth certain specific requirements for such latches. The ideal window grill latch will also satisfy certain other requirements. Foremost among these legal and ideal requirements are the following:
1. The window grill must be capable of being quickly and easily opened in the event of an emergency and at other times securely latched closed in a manner which provides the grill with a high resistance to forced entry by an intruder.
2. The window grill and its latch must be highly reliable in operation so as to assure easy opening of the grill in the event of an emergency.
3. The grill latch must be readily accessible to and easily operable by all potential users, including the young, elderly, and disabled, and its operation must be obvious without reading detailed instructions.
4. The grill latch must be immune to improper installation and to tampering, particularly by children which would cause malfunctioning of either or both the latch and window grill.
5. The grill latch must be immune to corrosion and other deterioration which would degrade the latch components or latch operation.
6. The grill latch should be automatically selflatching in order to encourage escape practice.
7. The window grill should open automatically in response to a fire near the window to permit rescuers to enter through the window even though the window grill latch cannot be released by persons in the burning structure.
8. The window grill latch should be capable of relatively low cost, high precision manufacture and easy to install.